Photographic material



United States Patent US. or. 96-29 9 Claims ABSTRACT OF THE DISCLOSURE The present invention relates to the use of 5,5-bis-1,2,4- triazoline-B-thiones or the tautomeric forms thereof as antibronzing and/or antisludge agents in photographic materials and processes.

The present invention relates to the use of 5,5-bis-1,2,4- triazoline-3-thiones for photographic purposes.

More particularly, the present invention relates to the use of 5,5'-bis-1,2,4-triazoline-3-thiones corresponding to the following general formula or tautomeric forms thereof:

A represents a chemical bond or a bivalent organic radical, more particularly a bivalent organic radical derived from an aliphatic dicarboxylic acid or from a dicarboxylic acid of carbocyclic or heterocyclic systems by removal of the carboxyl groups such as alkylene including substituted alkylene, arylene including substituted arylene, aralkylene including substituted aralkylene, cycloalkylene including substituted cycloalkylene or a bivalent heterocyclic radical including a substituted heterocyclic radical, and

each of R and R represents hydrogen, alkyl including substituted alkyl, aryl including substituted aryl or a heterocyclic radical including a substituted heterocyclic radical, at least one of R and R being a hydrogen atom, as antibronzing agents i.e. as agents for preventing the images obtained in light-sensitive silver halide emulsion layers of a photographic printing material from being bronzed by hot glazing or mechanical drying at elevated temperature and as anti-sludge agents to prevent the formation of metallic silver deposit in processing solutions for the silver complex diffusion transfer process.

It has been found that when incorporating compounds corresponding to the above general formula or tautomeric forms thereof into a light-sensitive printing material having at least one silver halide emulsion layer or into at least one of the processing baths for such material practically no loss of density i.e. no bronzing of the developed silver containing image occurs on hot glazing or drying at elevated temperature. Moreover, when said antibronzing agents are incorporated into one of the component layers of the light-sensitive material, they do not 'only prevent the silver-containing image from losing density on hot glazing or drying at increased temperature, but they also reduce the fog Without influencing the sensitivity and gradation to some noteworthy extent.

When incorporating the said antibronzing agents of use according to the invention into the photographic material, they are generally incorporated into the light-sensitive silver halide emulsion printing layer itself. They can be added to the printing silver halide emulsion at any moment during its preparation, but preferably after chemi- 3,438,777; Patented Apr. 15, 1969 cal ripening or just before coating. This addition occurs in general from a solution of the compound in an appropriate solvent such as water, alcohol, dimethylformamide, dioxan and so on. Instead of incorporating the compounds into the light-sensitive silver halide emulsion layer of the photographic printing material they can also be incorporated into at least one additional water-permeable layer coated at the same side of the support as the said emulsion layer. Evidently, mixtures of different compounds according to the above general formula may be used as well.

The total concentration of antibronzing agent of use according to the present invention in the light-sensitive printing material may vary within wide limits, but is preferably chosen in such a way that per sq. m. of light-sensitive material from some mg. to approximately 500 mg.

of this compound or compounds are present.

Light-sensitive printing material of use according to the present invention may comprise any printing silver halide emulsion layer such as for instance a gelatino silver chloride emulsion layer, a gelatino silver chlorobromide emulsion layer, a gelatin'o silver bromide emulsion layer, a gelatino silver bromoiodide emulsion layer and a gelatino silver chlorobromoiodide emulsion layer. The silver halide emulsion may contain all known additives, such as anti-fogging agents, stabilizers, hardening agents, plasticizers and dispersing agents. Further, the emulsion may be sensitized chemically as well as spectrally. It may be chemically sensitized by effecting the ripening in the presence of small amounts of sulphur containing compounds, for instance allyl isothiocyanate, allyl thiourea, sodium thiosulphate and so on. The light-sensitive printing emulsions can also be sensitized by means of reducing agents for instance the tin compounds described in the Belgian patent specifications 493,464 and 568,687, the iminoaminomethane sulphinic acid compounds described in the British patent specification 789,823 or by means of small amounts of noble metal compounds such as gold compounds, platinum compounds, palladium compounds, iridium compounds, ruthenium compounds and rhodium compound-s. Furthermore, it is also possible to sensitize the emulsions with polyoxyalkylene derivatives, for instance polyoxyethylene of a molecular weight ranging between 1000 and 20,000 or condensation products of alkylene oxides with aliphatic alcohols, glycols, cyclic dehydration products of hexitols, alkyl-su'bstituted phenols, aliphatic carboxylic acids, aliphatic amines, aliphatic diamines and aliphati amides. The condensation products have a molecular weight of at least 700, preferably of more than 1000. For attaining special effects these sensitizers, of course, can be applied in combination as described in the Belgian patent specification 537,278 and in the British patent specification 727,982.

Instead of incorporating the anti-bronzing compounds of use according to the invention into the photographic printing material prior to coating, they can be incorporated into the said material prior to hot-glazing or drying at elevated temperature by dissolving them in any processing bath such as the developing bath, the fixing bath, an additional hardening bath, and a bath, which contains surface-active compounds and which is used as a last treating bath before hot-glazing or before drying at elevated temperature of the image-containing material. When the photographic printing material is led through such a bath, it absorbs a certain amount of the said antibronzing agent into its waiter-permeable layers, which assures the retaining of the density of the silver-containing image during hot-glazing or drying at high temperature as successfully as in the case the anti-bronzing agent is present in the light-sensitive material from its preparation on. Evidently, for incorporating the anti-bronzing agents according to the invention into the photographic material said material can be treated prior to hot-glazing or drying at elevated temperature with a bath containing a mere solution of said anti-bronzing agents. When the anti-bronzing agents of use according to the invention are dissolved in one of the above baths, they are mostly dissolved in the form of their alkali salts in concentrations which can vary within very wide limits preferably, however, between approximately 50 mg. and approximately 3 g./litre.

Apart from being good anti-bronzing agents the compounds corresponding to the above general formula or a tautomeric form thereof have been found to prevent the formation of silver sludge in processing solutions for use in the photographic silver complex diffusion transfer process.

On carrying out the silver complex diffusion transfer process in developing apparatus known for this purpose the processing solution, which has been used for some time, will darken and finely divided metallic silver will precipitate therein. This silver precipitate called silver sludge will deposit on the guide elements so that said sludge is taken up by the material carried through the developer, thus producing stains on the diffusion transfer copies.

However, when carrying out the silver complex diffusion transfer process in the presence of at least one 5,5- bis-l,2, 4-triazoline-3-thione compound corresponding to the above general formula or a tautomeric form thereof no darkening of the processing solution and formation of silver sludge takes place.

In order to prevent the formation of sludge in processing solutions for use in the silver complex diffusion transfer process the compounds corresponding to the above general formula or a tautomeric form thereof must not necessarily be present in the processing solution itself but may also be incorporated into at least one waterpermeable layer of the image-receiving material.

The image-receiving material which can be used in a silver complex diffusion transfer process wherein the 5,5'-bis-1,2,4-triazoline-3-thiones or tautomeric forms thereof are used as anti-sludge agents, mostly consists of a support e.g. of paper which carries one or more layers, one of which is the image-receiving layer or nuclei-containing layer wherein the diffusion transfer image is formed in the presence of developing nuclei (physical and/or chemical) and/or of substances which are capable of forming developing nuclei with the diffusing complexed silver halide. The image-receiving material can also consist of a mere paper support incorporating constituents such as developing nuclei.

Also an image-receiving material can be used which is composed in such a way that several positive copies of an original can be produced from only one imagewise exposed light-sensitive material. Such an image-receiving material is among others described in the British patent specifications 950,960 and 961,177.

The image-receiving layer can also be applied to the same support as the silver halide emulsion layer. In that case, the image-receiving layer is mostly coated onto a support e.g. of paper and covered with a non-hardened or slightly hardened light-sensitive silver halide emulsion layer. Such a material is described among others in the British patent specification 654,631. After exposure, development and diffusion transfer of the unexposed complexed silver halide into the image-receiving layer, the exposed and developed unhardened emulsion layer can be removed e.g. by washing away with warm water or by stripping after having been in contact with a sheet of common paper. Between the image-receiving layer and the light-sensitive layer there can also be present a separating layer. In the British patent specification No. 1,006,292 is described a starch ether separating layer which enables the detaching of the light-sensitive layer as a coherent sheet, by simply bringing the multilayer material into an aqueous rinsing bath after the diffusion transfer image formation.

The light-sensitive material suitable for a diffusion transfer process wherein anti-sludge agents as described above can be used, may be any light-sensitive silver halide material the exposed silver halide of which is sufficiently rapidly developed and the non-exposed silver halide is sufiiciently rapidly complexed for allowing the formation of a diffusion transfer image to take place. Preferably silver chloride emulsions are used which may contain specific amounts of silver bromide or silver iodide or which some ingredients may be added in order to obtain the desired emulsion characteristics.

The developing substance(s) can be incorporated into the light-sensitive material and/or into the bath and/or into the image-receiving material. Suitable developing substances are among others: hydroquinone, monomethylp-aminophenol sulphate, aminophenol and 3-pyrazolidinone developing substances. Thus, hydroquinone together with a bisulphite can be present in the image-receiving material, as described in the British patent specification No. 1,000,115. Also combinations of two or more developing agents can be used successfully, such as the combination of hydroquinone and a 3-pyrazolidinone derivative together in the image-receiving material as described in the British patent application No. 1,012,476, the combination of hydroquinone in the image-receiving material and a 3-pyrazolidinone derivative in the light-sensitive material as described in the British patent applications Ser. Nos. 1,042,477 and 1,054,253 and the combination of hydroquinone and a 3-pyrazolidinone derivative in the light-sensitive material and hydroquinone in the image-receiving material as described in the British patent application Ser. No. 1,057,273.

The complexing agent forming a soluble complex with the silver halides is preferably an alkali thiosulphate and can be incorporated into the image-receiving material as well as into the processing bath.

Sulphides of heavy metals such as of antimony, bismuth, cadmium, cobalt, lead, nickel and silver; heavy metals such as silver, gold, platinum, palladium and mercury, preferably in their colloidal form, and/or other substances which can serve as developing nuclei for the complexed silver halide are mostly incorporated into the image-receiving layer. However, they can also be present in the processing bath. In the latter case, use is made of a light-sensitive and image-receiving material with a specific composition. Such diffusion-transfer process with developing nuclei and/or compounds capable of forming such nuclei present in the processing bath has among others been described in the British patent specification No. 1,001,558 and in the British patent application Ser. No. 1,052,022.

In many cases it is favourable to counteract the fog formation in the exposed silver halide emulsion layers by using a fog-inhibiting agent. This fog-inhibiting agent, e.g., can be present in the light-sensitive silver halide material and/ or in the processing bath.

All the ingredients such as developing substances, complexing agents for silver halide, alkali, developing nuclei and the like which are necessary in a silver complex diffusion transfer process can be incorporated into the lightsensitive and/or image-receiving material used so that occasionally common water can be used in processing liquid. A suchlike process is described in the British patent specification No. 1,013,343.

Particulars concerning the exposing and developing apparatus that can be used as well as the silver complex dif fusion transfer process in general and the materials suitable therefor, can be found in Progress in Photography, vol. I, 1940-1950, pp. 76, 77 and vol. II, 1951-1954, pp. 156157; vol. III, 19551958, pp. 2436 and in the patent literature cited therein.

The amount of 5,5'-bis-1,2,4-triazoline-3-thione corresponding to the above general formula or a tautomeric form thereof, used for preventing the formation of metallic silver deposit in silver complex diffusion transfer processing liquids may vary within wide limits say from about 0.1 g. to about 3 g. per litre, when incorporated in the developing solution and from about 1 mg. to about 20 mg. per sq. m. when applied in an image-receiving material for use in the silver complex diffusion transfer process.

The 5,5-bis-1,2,4-triazoline-3-thiones corresponding to the above general formula or tautomeric forms thereof, which are suitable for use as anti-bronzing agents in lightsensitive printing material or in at least one of the processing solutions for such material and for use as antisludge agents in the silver complex diifusion transfer process, can be prepared by cyclisation of thiosemicarbazide, 4-substituted thiosemicarbazide or 2-substituted thiosemicarbazide, e.g., 4-methyl-thiosemicarbazide, 4-phenyl-thiosemicarbazide, 4-(p-chlorophenyl)-thiosemicarbazide, 4- (p-ethoxyphenyl)-thiosemicarbazide, 4-a-pyridylthiosemicarbazide, 2-methyl-thiosemicarbazide, and so on, with dicarboxylic acid esters in an alcoholate medium analogously to the method described in Bull. Soc. Chim. France (1961) 1581 for the preparation of 5-substituted 1,2,4-trilitre of water. The insoluble unreacted thiosemicarbazide is filtered off and the filtrate is acidified with acetic acid. The 5,5'-bis-1,2,4-triazoline-3-thione, which precipitates in acid medium, is filtered by suction and purified by recrystallization from water or ethanol or a mixture of both. The slightly water-soluble products are treated with boiling water to remove the unreacted thiosemicarbazide. This treatment is continued until the test with ammoniacal silver nitrate, which forms silver sulphide with the thiosemicarbazide if present, is negative. In some cases it may be advisable to treat the 5,5 '-bis-1,2,4-triazoline-3-thiones, after they have been separated, with dichloroethane or chloroform in order to remove the hardly water-soluble dicarboxylic acids which form as by-products.

When the dicarboxylic acid ester is an ester of an aliphatic unsaturated dicarboxylic acid the resulting 5,5-bis- 1,2,4-triazoline-3-thione will show no double bond(s) any more owing to the addition of an alkoxy group or groups, which group(s) depend on the alcoholate medium applied.

As an illustration of the above general procedure some concrete data are listed in the following table of the preparation of some specific 5,5'-bis-1,2,4-triazoline-3-thiones corresponding to the above general formula.

M.P. Yield, Anal sis, me R R; A C. percent Ester used Cale. Found H H 260 27 Diethyl oxalate 10. 00 9. 70 H H CH2 260 45 Diethyl malonate 9. 35 9. 26 H H CHCHs 260 15 Dietilziyl methyl male 8. 77 8. 77

na e. H H OHCQHE 260 20 Diethyl ethyl malonate- 7. 69 8. 76

(hydrate) H H (OH2)2 260 66 Diethyl succinate 8. 77 7. 58 H H (CH2)3 260 63 Diethyl glutarate- 8. 26 8. 14 H H (CH2)4 260 54 Diethyl adipate 7. 81 7. 64 H H (CHM 260 84 Diethyl sebaeate- 6. 41 6. 57 H H (CHOH); 260 38 Diethy1tartrate-. 7. 69 7. 03

H H (111C132 260 39 Diethyl fuluarate. 7. 75 7. 73

O CH:

H H (IJHGHZ 260 Diethyl maleate 7. 75 7. 63

O OH:

H H CHCH; 260 15 Diethyl fumarate (re- 7. 7. 16

action in ethanol with 0 C2115 sodium ethylate) H H 1, 3-CtH4 260 48 Dimethyl isophthalate. 7. 25 7. 51 H H 1, 4-CBH4 260 65 Diltl'letllyl terephthal- 7. 25 7. 15

a e. OH; H 1, 4-CtH4 260 74 do 6. 58 6. 60 H CH3 1, 4-C0H4 260 56 d0 6. 58 6. 63 H 2, G-CwHa 160 76 2, fi cdimethyl naptho- 0. 13 6. 08

azoline-3-thiones by cyclisation of 4-substituted thiosemicarbazide with monocarboxylic acid esters.

As dicarboxylic acid esters may be used esters of aliphatic dicarboxylic acids and of dicarboxylic acids of carbocyclic and heterocyclic systems. Some examples of suitable esters are the esters of oxalic acid, malonic acid, methyl and ethyl malonic acid, succinic acid, glutaric acid, adipic acid, sebacic acid, tartaric acid, fumaric acid, maleic acid, terephthalic acid, isophthalic acid, 2,6-naphthalene dicarboxylic acid, 1,4-dicarboxycyclohexane, 2- carboxy-2-methyl-cyclohexane acetic acid, 3,5-dicarboxypyridine, 3-carboxy-cinnarnic acid, and so on.

It appears to be of no importance what kind of ester is used since it has been experienced that the yields are practically the same whatever esters are used say the methyl esters, the ethyl esters, the isopropyl esters or the t-butylesters.

The following general procedure illustrates how the 5,5'-bis-1,2,4-triazoline-3-thiones according to the above general formula can be prepared.

To a sodium alcoholate solution prepared from 1 litre of methanol and 1 mole of sodium are added 1 mole of thiosemicarbazide and 0.5 mole of a dicarboxylic acid ester. The mixture is boiled for 16 hours. During the reaction the sodium salt of the 5,5-bis-1,2,4-triazoline-3- thione crystallizes. After the reaction, the solvent is removed by evaporation and the residue is dissolved in 1 The products obtained were analysed by potentiometric titration with potassium methylate in dimethyl formamide.

The following examples illustrate the use of the 5,5-bisl,2,4-triazoline-3-thiones according to the above general formula as anti-bronzing agents and anti-sludge agents as described above without however limiting the scope of the invention thereto.

EXAMPLE 1 Material 1 Materials 2-14 These materials are prepared in the same way as material 1 with the difference however that. per kg. of lightsensitive emulsion ready for coating, the compounds listed in the table hereinafter are added in the amounts given from an aqueous alkaline solution.

Material Compound MgJ 2 Bis (3-thioxo-1,2,4-triazolin-5-yl) 200 4 1,2-bis (3-thioxo-1,2,4-triazolin-5-yl) -ethane 228 5 l,3-bis(3-thioxo-l,2,4-triazolin-5-yl) propane. 242

6. 1,4-bis(3-tl1ioxo-1,2,4-triazolin-5yl)-butane 256 7 1,8-bis(3-thioxo-1,2,4-triazolin5-yl)-ootane 31 2 8 1,2-tbhis(3-thioxo-1,2,4-triazolin-5-yl)-1,2-dihydroxy- 260 e ane.

9 1, l-bis (3-thioxo-l,2,4-triazolin-5-yl)-ethane 228 10 1,1-bis(3-thioxo-1,2,4-triaz01in-5-yl)-propane- 260 by rate.

11 1,2-bis (3-thioxo-1,2,4-triazolin-5-yl)-methoxy- 258 eth ane.

12. 1,3-bis(3-thioxo-1,ZA-triazolin-Eyl)-benzene 276 14 2,6-bis (3-thiox0-1,2,4-triaz0lin-5-yl)-naphthalene. 326

A strip of each of these 14 materials is exposed for some minutes and developed for five minutes at C. in a bath of the following composition:

Water ccs 800 p-Monomethyl-aminophenol sulphate Anhydrous sodium sulphite Hydroquinone Anhydrous sodium carbonate Potassium bromide Water, up to 1000 ccs.

The 14 material strips are rinsed for a moment and then fixed for five minutes at room temperature in the following composition:

Water ccs 800 Anhydrous sodium thiosulphate g 120 Potassium meta-bisulphite g Water, up to 1000 ces.

The 14 material strips are finally pressed for 6 minutes with their image-containing side against a polished plate of 80 C.

The density of the various material strips is measured with a Macbeth densitometer before as well as after hot glazing. The following results are attained:

Density before Density alter hot glazing hot glazing Material:

Comparison material.

From these results it clearly appears that the 5,5-bis- 1,2,4-triazoline2-thione compounds have an anti-bronzing action.

EXAMPLE 2 Material 1 Materials 2-14 These materials are prepared in the same way as material 1 with the difference however that per kg. of lightsensitive emulsion ready for coating, the compounds listed in the table of Example 1 are added in the amounts given.

A strip of each of these 14 materials is treated in the same way as the material strips of Example 1. The following results are attained:

Density before Density after hot glazing hot glazing Material:

1* 1. 96 1. 67 1. 98 2.02 2. 00 2. l2 1. 06 2. 11 1. 93 2. 05 1. 96 2. l2 1. 94 1. 94 1. 95 1. 94 1. 94 1. 94 1. 95 1. 98 1. 96 2. 05 1.96 2.07 1. 96 2. 04 l. 92 1. 97

*Comparison material.

From these results it clearly appears that the compounds of the invention have an anti-bronzing action.

EXAMPLE 3 Material 1 Materials 2-14 These materials are prepared in the same way as material 1 with the difference however that per kg. of lightsensitive emulsion ready for coating, the compounds listed in the table of Example 1 are added in the amounts given.

A strip of each of these materials is treated in the same way as the material strips of Example 1 and the following results are attained:

Density before Density after hot glazing hot glazing *Comparison material.

From these results it clearly appears that the compounds of the invention have an anti-bronzing action.

EXAMPLE 4 In a developing solution of the following composition:

(3. Sodium sulphite (anhydrous) Sodium hydroxide 10 Potassium bromide Hydroquinone 1-phenyl-3-pyrazolidinone Water, to 1000 ccs.,

a black sludge begins to deposit when about 60 silver complex diffusion transfer copies are produced. This sludge formation increases with the number of diffusion transfer copies made. The diffusion transfer copies obtained with the aid of a developing bath containing said sludge show black spots.

When per litre of developing solution 700 mg. of 1,3- bis-(3 thioxo-1,2,4-triazolin--yl)-propane is added, the solution remains clear and can be used until complete exhaustion without silver sludge formation.

The same favourable effect is obtained when incorporating in said developing solution 700 mg./litre of l,8-bis(3- thioxo-1,2,4-triazolin-5-yl)-octane or 1,1-bis(3-thioxo-1,2, 4-triazoline-5-yl)-propane hydrate.

EXAMPLE 5 An image-receiving material is prepared by coating a 90 g./ sq. m. paper support in a ratio of 20 sq. m./litre with a layer from a suspension of the following composition:

Water ccs 800 Gelatin g 40 Sodium thiosu1phate-5 water g 48 Aqueous sodium sulphide ..ccs.. 2.5 Aqueous cobalto nitrate (10%) ccs 13 Solution of l-phenyl-2-tetrazoline-S-thione in ethanol 1% ccs 5 Aqueous formaldehyde (20%) cos-.. 5

Sandozol (trade name for a sulphonated organic oil marketed by Sandoz A.G., Basel, Switzerland) ccs 1 Water, to 1000 ccs.

A gelatino silver chloride emulsion paper containing per sq. m. an amount of silver chloride equivalent to 1.35 g. of silver nitrate is exposed while being in contact with an original to be reproduced, whereupon it is led together with the above mentioned image-receiving material through a developing bath of the composition given in Example 4.

When about 60 silver complex diffusion transfer copies are produced a black sludge deposits in the developing bath and the copies obtained begin to show black spots.

If on the contrary, an image-receiving material is used having the same composition as the one above but comprising in addition thereto per sq. m. 4 mg. of bis(3- thioxo-l,2,4-triazolin-5-yl)-methane the developing bath remains clear and can be used until exhaustion without silver sludge being formed. 7

The same favourable result is obtained when incorporating into the image-receiving material 4 mg./ sq. m. of 1,3-bis(3-thioxo-l,2,4-triazolin-5-yl)-propane, 1,1 bis(3- thioxo-1,2,4-triazolin-5-yl)-propane 1 water or 1,3-bis (3-thioxo-1,2,4-triazolin-5-yl)-benzene respectively.

EXAMPLE 6 A light-sensitive material is prepared by coating a paper support of 90 g./ sq. m. with a gelatino silver chloride emulsion containing l-phenyl-3-pyrazolidinone and hydroquinone in such a way that per sq. m. an amount of silver chloride equivalent to 0.8 g. silver nitrate, 0.5 g. of 1-phenyl-3-pyrazolidinone and 1 g. of hydroquinone are present. The light-sensitive silver chloride emulsion layer is then overcoated with a hydroxyethyl cellulose layer pro rata of 0.5 g./ sq. 111.

An image-receiving material is prepared by coating onto a paper support of 90 g./sq. m. a thin layer from a suspension of the following composition pro rata of 1 litre per 30 sq. m.: I

Water ccs 600 Gelatin ..g 30 Aqueous sodium sulphide (10%) ccs 2.5 Aqueous cobalt nitrate (10%) ccs 13 Hydroquinone g 7.5 Potassium metabisulphite g 37.5

water, up to 1000 ccs.

The light-sensitive material is now image-wise exposed and together with the image-receiving: material passed through a common diffusion transfer developing apparatus containing a processing solution of the following composition:

Water ccs.. 1000 Trisodium phosphate-lZ-water g 75 Sodium sulphite (anh.) g 40 Potassium bromide g 0.5 Sodium thiosulphate (anh.) g- 10 1,3 bis(3 thioxo-1,2,4-triazolin-5 yl) propane Even when the above processing solution is frequently used for making diffusion transfer copies as described no silver sludge formation takes place and said solution remains completely clear, which is not the case when said solution comprises no 1,3-bis(3-thioxo-1,2,4-triazolim5- yl) -propane.

EXAMPLE 7 Example 6 is repeated with the difference however that the processing solution comprises no 1,3-bis(3-thioxo-1,2, 4-triazolin-5-yl)-propane and that to the suspension from which the image-receiving layer is coated an amount of 1,3-bis(3-thioxo-1,2,4-triaZolin-5-yl)-propane is added in such a way that after drying 4 mg. of said compound are present per sq. m.

The same favourable results are obtained as in Example 6.

We claim:

1. Photographic printing material comprising a support and at least one light-sensitive silver halide emulsion layer, wherein the light-sensitive silver halide emulsion layer and/or at least one water-permeable layer coated at the same side of the support as the said emulsion layer contains at least one 5,5'-bis-1,2,4-triazoline-3-thione corresponding to the following general formula or tautomeric form thereof:

' each of R and R is hydrogen, an alkyl group, an aryl group or a heterocyclic group, at least one of R and R being hydrogen, and

A is a chemical bond or an organic bivalent radical,

derived from an aliphatic dicarboxylic acid or a dicarboxylic acid of a carbocyclic o a heterocyclic system by removal of the carboxyl groups.

2. Photographic printing material according to claim 1, wherein said organic bivalent radical is an alkylene radical, an arylene radical, an aralkylene radical, a cycloalkylene radical or a bivalent heterocyclic radical.

3. Photographic printing material comprising a support and at least one light-sensitive silver halide emulsion layer, wherein the light-sensitive silver halide emulsion layer and/or at least one water-permeable layer coated at the same side of the support as the said emulsion layer contains at least one cyclisation product of thiosemicarbazide, Z-substituted thiosemicarbazide or 4-substituted thiosemicarbazide with an ester of an aliphatic dicarboxylic acid, a dicarboxylic acid of a carbocyclic system or a dicarboxylic acid of a heterocyclic system.

4. Photographic processing bath contain at least one 5,5'-bis-1,2,4-triazoline-3-thione corresponding to the following general formula or tautomeric form thereof:

wherein each of R and R is hydrogen, an alkyl group, an aryl group or a heterocyclic group, at least one of R and R being hydrogen, and

A is a chemical bond or an organic bivalent radical, derived from an aliphatic dicarboxylic acid or a dicarboxylic acid of a carbocyclic or a heterocyclic system by removal of the carboxyl groups.

5. Process for hot-glazing or mechanically drying at elevated temperature image-wise exposed, developed and fixed photographic material, wherein said photographic material when being hot-glazed or dried contains at least one 5,5-bis-1,2,4-triazoline-3-thione corresponding to the following general formula or tautomeric form thereof:

each of R and R is hydrogen, an alkyl group, an aryl group or a heterocyclic group, at least one of R and R being hydrogen, and

A is a chemcial bond or an organic bivalent radical,

derived from an aliphatic dicarboxylic acid or a dicarboxylic acid of a carbocyclic or a heterocyclic system by removal of the carboxyl groups.

6. Photographic silver complex diffusion transfer process according to which a positive image of an original is obtained by development of an image-wise exposed light-sensitive silver halide emulsion layer and diifusion of the non-developed complexed silver halide from the emulsion layer to an image-receiving material where the complexed silver halide is converted into a silvercontaining image in the presence of development nuclei or substances capable of forming such nuclei, wherein said process is carried out in the presence of at least one 5,5'-bis-1,2,4-triazoline-3-thione corresponding to the following general formula or tautomeric form thereof:

each of R and R is hydrogen, an alkyl group, an aryl group or a heterocyclic group, at least one of R and R being hydrogen, and

each of R and R is hydrogen, an alkyl group, an aryl group or a heterocyclic group, at least one of R and R being hydrogen, and

A is a chemical bond or an organic bivalent radical, derived from an aliphatic dicarboxylic acid or a dicarboxylic acid of a carbocyclic or a heterocyclic system by removal of the carboxyl groups.

9. Processing bath according to claim 4, for use in a silver complex diffusion transfer process.

References Cited UNITED STATES PATENTS 2,573,027 10/1951 Kendall et al. 96-52 2,590,775 3/1952 Kendall et a1. 9696 3,068,098 12/1962 Williams 96-52 3,359,106 12/1967 Willems 96-52 NORMAN G. TORCHIN, Primary Examiner.

G. COHN, Assistant Examiner.

US. Cl. X.R. 9652 222 3 UNITED STATES PATENT: OFFICE CERTIFICATE OF CORRECTION Patent No. 3 438 777 4 L Dated April 15 1969 Inventor(s) Jozef Frans Willems et ,al

It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 4 line 12, after "or" insert to Column 6, in the Table, column 4 line 17 delete 160" and insert 7260 column 8, line 4, delete "8.76" and insert 7.76 column 8 line 5 delete "7. 58" and insert 8. 58 Column ll, lines 15 to 19, the formula should appear as shown below:

N N 12 -1; c- A-T NR S=C-- N-R RN C=S line 24, "chemcial" should read chemical SIGNED AND SEALED JUN 3 01970 .Attest:

ILLIAM E. 'SGHUYLER, JR. Ed M Fletcher ya Commissioner of Patents A iesfing Officer 

